Cleaning of metals by electrolysis



Patented May 6, 1924.

I UNITED STATES 1,493,205 PATENT OFFICE.

ISIDORE JASCOWITZ AND JOHN ROSENBAUM, OF LONDON, ENGLAND, ASSIGNORS. TO

R. J. CORPORATION, LIMITED, OF LONDON, ENGLAND.

CLEANING OF METALS BY ELECTROLYSIS.

No Drawing. Application filed May 4,

T 0 all whom it may cam (era Be it known that we, Ismonn JAsoowrrz and JOHN ROSENBAUM, subjects of the King of Great Britain. residing at 66 Greenfield Street, London, E.. England. have invented a new and useful Cleaning of Metals by Electrolysis (for which we have filed application in Great Britain August 22, 1918, No. 13,642) and we do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appert-ains to make and use the same.

This invention relates to a novel process for'the electrolytic cleaning of metal articles.

It has been proposed to remove scale and oxide from metal plates, wires, strip or ribbon by passing the said plates or the like through an electrolytic solution consisting of a weak solution of sulphuric or hydrochloric acid or caustic soda.

Now this invention consists in the utilization of an improved electrolyte in which the metal articles to be cleaned are suspended or placed in an electrolytic-vat, in electrical connection with the cathode, the anodes being suitably made of iron. The electrolyte consists of spent caustic melt solution, obtained in the fusion process in the manufacture of a variety of chemicals such as B- Ilaphthol, phenol, alizarine, resorcin, and is a compound of caustic soda and sulphite, sulphate and carbonate of sodium, together with organic residues. As a typical melt may be taken a residue obtained in the man ufacture of phenol and which would have a composition approximately as follows By weight. Caustic soda Sodium sulphite 28% Sodium sul hate 8% Sodium car onate 8% Phenol (traces) say 1to 2% 1921. Serial 110.466,?10.

20 per cent and is, in practice advantageously heated to a temperature of about 90 C.

By the process it is found possible to remove from iron, steel and other metal articles. all oils. fats, greases, paints, rust and scale with which their surfaces have become coated and to produce thoroughly clean surfaces, thus obtaining in a single process or operation a result which has heretofore only been obtainable by subjecting the articles to be cleaned to two distinct operations. The process, therefore, effects an economy in time and labour.

Claims:

1. The herein described process for the electrolytic cleaning of iron, steel and other metals, which consists in subjectin the article to be cleaned to electrolytic action in an electrolyte containing a large proportion by weight of caustic soda, a smaller proportion by weight of sodium sulphite, and smaller proportions by weight of sodium sulphate and sodium carbonate.

2. The herein described process for the electrolytic cleaning of iron, steel and other metals, which consists in subjecting the article to be cleaned to electrolytic action in an electrolyte containing a large proportion by weight of caustic soda, a smaller proportion by weight of sodium sulphite, and smaller proportions by weight of sodium sulphate and sodium carbonate, and smaller quantities of phenolate and salicylate of soda.

3. The herein described process for the electrolytic cleaning of iron, steel and other metals, which consists in subjecting the article to be cleaned to electrolytic action in an electrolyte containing approximately 50% by weight of caustic soda, 28% by weight of sodium sulphite, and 8% by weight each of sodium sulphate and sodium carbonate.

4. The herein described process for the electrolytic cleaning of iron, steel and other metals, which consists in subjecting the article to be cleaned to electrolytic action in an electrolyte containing approximately 50% by weight of caustic soda, 28% by weight of sodium sulphite, and 8% by weight each of sodium sulphate and sodium carbonate, and 1.5% by weight of phenolate of soda.

5. The herein described process for the electrolytic cleaning of iron, steel and other metals, which consists in subjecting the article to be cleaned to electrolytic action in an electrolyte containing approximately 50% by weight of caustic soda, 28% by weight of sodium sulphite, and 8% by weight each of sodium sulphate and sodium carbonate, and 1.5% by weight of salicylate of soda.

6. The herein described process for the electrolytic cleaning of iron, steel and other metals, which consists in subjecting the article to be cleaned to electrolytic action in an electrolyte consisting of a spent caustic melt 10 solution obtained in the fusion process in the manufacture of chemicals such as B-naphthol, phenol, alizarine and resorcin, and con taining a large proportion by weight of caustic soda, a smaller proportion by weight of sodium sulphide, smaller proportions by weight each of sodium sulphate and sodium carbonate.

ISIDORE 'JASGOWITZ. JOHN ROSENBAUM. 

